Tallow, which is animal fat derived from the rendering of cattle and other sources such as sheep, is a primary feedstock for the production of fatty acids and glycerin. A hydrolysis reactor, also known as a “splitter” in the fatty acid industry, is used to hydrolyze fat into fatty acid and glycerin. These reactors operate at conditions exceeding the requirement of the regulations to produce heated treated fatty acids. The tallow is fed into the lower part of the splitter. Conversion of fat to fatty acids occurs as this material moves up through the reactor column. The fatty acids are removed from the top of the reactor column. Due to the design of these splitters, the fat feed that enters near the bottom, contacts and cools the sweet water (dilute glycerin) that flows to the bottom. The sweet water along with some entrained and untreated fat are then removed from the bottom of splitter. This process is described in U.S. Pat. No. 2,156,863, the entire contents of which are incorporated herein by reference.
Prions are small, proteinaceous infectious particles that resist inactivation by procedures which affect nucleic acids. Prions, which is an acronym that stands for “proteinaceous infectious particle”, are generally believed to be the causative agents for a family of diseases known as “transmissible spongiform encephalopathy” (TSE). Prions are composed largely, if not entirely, of a protein designated as the scrapie isoform of the prion protein, PrPSc.
BSE (bovine transmissible spongiform encephalopathy) is the cow version of TSE, popularly known as mad cow disease. In humans the disease as transmitted from cows is called variant or new variant Creutzfeldt-Jakob Disease (vCJd or nvCJD). Some researchers believe that the prions are DNA-free and RNA-free protein particles which either self-replicate, or induce replication by interaction with normal proteins, in the nervous systems of various mammals and ultimately cause the formation of deposits/platelets in the brain which leads to dementia-like symptoms and death.
Glycerin that is produced from fat from cows having mad cow disease can be contaminated with prions. This problem has been especially acute in Europe where mad cow disease has been prevalent in the past few years. European governmental health regulating authorities have prescribed conditions under which it is believed that the prions can be sufficiently treated so as to limit the spread of mad cow disease. These conditions are set forth in two European Union directives—the Twenty-second Commission Directive 98/16/EC of Mar. 5, 1998 and Twenty-fourth Commission Directive 2000/6EC of Feb. 29, 2000 relating to cosmetic products. One of the prescribed treatments requires exposure of the potentially contaminated material, such as glycerin produced from the splitting of prion-contained tallow, to conditions of at least 200° C. (392° F.) for a minimum of 20 minutes, under appropriate pressure, and in the presence of water.
Because glycerin and water from a fat splitting process can be contaminated with prions, there is a need for a reliable process that will produce glycerin and water containing only deactivated prions.